1. Field
The present invention relates to a fuel cell system.
2. Description of the Related Art
A fuel cell system typically includes a fuel cell stack that generates electrical energy using electrochemical reaction of a fuel (hydrocarbon-based fuel, pure hydrogen, or reformed gas rich in hydrogen) and an oxidizing agent (air or pure oxygen). A direct oxidation type of fuel cell uses a liquid or gas hydrocarbon-based fuel, and a polymer electrolyte type of fuel cell uses pure hydrogen or a reformed gas rich in hydrogen.
The fuel cell stack includes a plurality of membrane electrode assemblies (MEAS) and separator located between each adjacent MEAS.
The MEA includes an electrolyte membrane, an anode formed at one side of the electrolyte membrane, and a cathode formed at the other side of the electrolyte membrane. The separator forms a fuel channel at one side facing the anode to supply a fuel to the anode, and forms an oxidizing channel at one side facing the cathode to supply an oxidizing agent to the cathode.
A large home fuel cell system is equipped with a humidifying device for fuel humidification and a humidifying device for humidification of an oxidizing agent to control humidity of a fuel or an oxidizing agent supplied to a fuel cell stack. However, in this case, water should be continuously supplied to the humidifying device and a heater and various sensors are required for temperature control, thereby increasing the volume of the fuel cell system and the number of parts required.
A mobile fuel cell system used for vehicles may include a reformer as a hydrogen generation device. In this case, a large amount of moisture is included in a fuel so that a moisture control device is required to continuously eliminate a constant amount of water, and a cooling device and various sensors and control devices are required for the moisture control so that the volume of the fuel cell system is increased and the number of parts is also increased.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.